1. Field of the Invention
The present invention relates to a train control system, and more specifically, relates to a train control system that can determine that a ground device has failed, to reliably prevent a train from entering a control section of the failed ground device.
2. Description of Related Art
Conventionally, in a train control system using a so-called radio distance measurement system, a vehicle radio set is mounted on a train, and a wireless network is formed between the vehicle radio set and a plurality of wayside radio sets, which is spatially separated and disposed along a wayside of a track on which the train travels, and then, a wireless propagation delay (time) between an on-board antenna of the vehicle radio set and a wayside antenna of the wayside radio set is measured, to detect a train location, so that the train control is performed based on the detected train location.
Furthermore, as such a train control system using the radio distance measurement system, conventionally, for example, a technique including: a wireless train location detecting unit that detects a train location on a predetermined track based on a propagation time of a radio wave between a vehicle radio set mounted on a train travelling on the predetermined track and a ground radio set disposed at a predetermined location on the ground; a travel distance calculating unit that calculates a travel distance of the train on the predetermined track based on an output signal of a tachometer generator connected to an axle of the train; a temporary reference location setting unit that sets the detected train location detected by the wireless train location detecting unit as a predetermined temporary reference location; and a train location detection calculating unit that detects a train location on the predetermined track based on the travel distance calculated by the travel distance calculating unit based on the temporary reference location set by the temporary reference location setting unit, has been disclosed (see, Japanese Laid-open Patent Application Publication No. 2007-331629, for example).
However, in the conventional technique, although there is no problem while each ground device is normally operated, there might have been a problem when a ground device fails, that is, the ground device may fail to transmit information to and receive information from a wayside radio set controlled by the failed ground device. When the ground device has thus failed, there might be a problem in that the transmission of information to and reception of information from the train may fail, so that a location of the train cannot be detected, and thus, travel control of the train cannot be performed, that is, it is extremely dangerous. In addition, there might be another problem in that once the ground device has failed, a complicated restoring work may be required.